Piano construction.



PATENTED MAR. 22, 1904.

P. M. ZEIDLER. PIANO GONSTRUGTION.

APPLICATION FILED JULY 10, 1903. N0 MODEL. 2 sums-sum 1.

NO MODEL.

PATENTED MAR. 22, 1904.

P. M. ZEIDLER.

PIANO CONSTRUCTION.

APPLICATION FILED JULY 10,1903.

2 SHEBTS-SHEET 2.

' UNITED STATES Patented March .22, 1904:.

PATENT OFFICE.

PAUL MARTIN ZEIDLER, OF NEW YORK, N. Y.

PIANO CONSTRUCTION.

SPECIFICATION forming part of Letters Patent No. 755,341, dated March 22, 1904.

Application filed July 10, 1903.

T0. ctZZ whom it may concern:

Be it known that I, PAUL MARTIN ZEIDLER, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Piano Constructions, of which the following is a specification suflicient to enable others skilled in the art to which the invention appertains to make and use the same.

My invention is designed more particularly for use in grand and upright pianos, the object being to insure the maintenance of the original form given to the rim-case upon which the sound-board is mounted,at the same time dispensing with the wooden braces here tofore used, which have a tendency to deaden the tone of the instrument. I thus increase the resonance of the sound-board and permanently augment its volume of tone.

The invention consists, essentially, in a series of stay rods the outer extremities of which are connected with or bear upon the sound-board rim and rim-brace in substantially the same plane and the inner extremities of which are connected tangentially to a centralizing-hub in two planes, one on each side of the central plane in which the said outer extremities of the stay-rods are arranged, so that the sound-board rim is practically trussed internally against the enormous strain to which it is subjected by the strings of the instrument acting through the sound-board, such strain being received and distributed uniformly over the whole rimcase by the centralizing-hub, which is free to adjust itself to all variations or inequalities of tension exerted upon and through the stayrods.

My invention also includes certain other details'in the construction and arrangement of parts hereinafter described and claimed specifically. y

In the accompanying drawings, Figure 1 represents aplan of the under side ofa sounding-board rim-case to which my invention is applied, all the non essential parts being omitted. Fig. 2 is asection upon plane of line 2 2, Fig. 1. Fig. 3 is a section upon plane of line 3 3, Fig. 1. Fig. 4 is an elevation of one end of the centralizing-hub; Fig. 5, a side Serial No. 164,944. (No model.)

elevation of'the same; Fig. 6, a transverse section upon plane of line 6 6, Fig. 5; Fig. 7, a longitudinal section upon plane'of line 7 7, Fig. 4:, the stay-rods being omitted. Fig. 8 is a sectional view of a portion of the sounding-board rim, showing an elevation of one of the socket-pieces embedded in the inner rim. Fig. 9 is a similar view showing the nut-bearing'piece also in section. Fig. 10 is a view of the inner side of the socket-piece; Fig. 11, a view of the opposite side of said socket-piece; Fig. 12, a section taken upon plane of line 12 12, Fig. 8.

I herein show and describe simple and effective means whereby the principle of my invention is adapted in practical form to the case U of a sounding-board B, although I do not confine myself to the identical form and arrangement of parts shown, since it is obvious that various mechanical expedients may be resorted to without departing from the spirit and intent of my invention. For instance, the centralizing-hub H is preferably, though not necessarily, of cylindrical form, although a polygonal or other form might be used with like result. Various mechanical expedients other than those shown may also be resorted to in connecting the stays S S with the inner rim R, the rim-brace R and centralizing-hub H, although one of the features of my invention is a self-adjusting bearing between the stay-rods S and the rim R and brace R of the case C.

As shown herein by way of illustration, the cylindrical hub H is formed with a series of peripheral lugs Z Z, formed with holes or perforations Z Z, through which the stays S S are passed. These lugs may be formed directly upon the hub H, if preferred, although I have shown them as forming part of each of the flanged caps 0 c, which are secured to the ends of the cylindrical hub H by pins 0' 0 or other suitable means. The lugs Z Z extend radially from the centralizing-hub H, which latter may be made of a length axially slightly less than the crosssection of the sounding-board rim R and rim-brace R as shown in Figs. 2 and 3, so as to provide amply for the trussing of said rim, as hereinafter set forth.

The inner ends of the stay-rods S S are formed with heads or flanges .s a, which rest and bear upon the lugs Z Z when the stays S S are drawn taut. These heads .s's are preferably of square or other polygonal form to adapt them for engagement with a wrench or other similar-tool when necessary. The outer ends of the stay-rods S S are formed with male screwthreads 8 s, which engage with the female screw-threads 02, formed in the bearing-nut N. A portion of the bearing-nut N is formed with one or more flat surfaces 71/ for engagement with a wrench or similar instrument by which the nut may be rotated on its axis to tighten or loosen it upon the threaded end of the stay-rod S. The bearing-nut N is also formed with a partly-spherical bearing-head a for engagement with a correspondinglyformed-concave bearing-surface j), formed in the socket-piece P, the head 12 and the bearingsurface 1) constituting, practically,a universal or ballandsocket joint, so that the stay-rod S and bearing-nutN are free to adaptthemselves axially to the direct line of tension exerted when the bearing-nutis rotated upon the stayrod S to tighten the same. Here, again, it is evident that other well known and equivalent mechanical expedients may be employed for coupling the stay-rod S and the bearing-head 01 together with like effect, the result sought and attained being a connection between the stay-rod S and the sounding-board rim R and rim-brace R that will allow the parts to adapt themselves automatically to perfect alinement in the shortest possible distance between the socket-piece P and the lug l upon the centralizing-hub H. The inner section R of the rim is glued to the outer section R and to the rimbrace R so as to form an integral part thereof, and this fact is of importance in the consideration of my invention, which is not designed to effect the compression of the rimcase as a whole or any part thereof, but for the sole purpose of permanently maintaining the rim as a whole in its original shape-that is to say, the shape in which it was when the sound-board was glued to it. To this end the socket-pieces P are arranged in a common plane, or substantially so, in the rim R and rimbrace R said plane coinciding approximately with the middle of the inner rim R in crosssection. Alternate stay-rods S are connected with lugs on opposite ends of the centralizinghub H, as will be understood by reference to Figs. 2 and 3, so that the rim is to all intents and purposes trussed internally against change of form in proportion to the degree of tension imparted to the stay-rods, which are so distributed as to connect through the centralizing-hub the weakest and strongest points in the sounding-board rim-case. As a result inequality of pressure is counteracted, the same degree of strain being attained and maintained in all parts of the rim-case, thereby imparting a uniform even tension to the sound-board, in-

creasing its vibratory capacity, and augment ing and imposing its quality of tone. This result is contributed to largely by the tangential arrangement of the stay-rods S with relation to the centralizing-hub H, which latter is absolutely free of connection or contact with anything but the stay-rods, so that it can freely adapt itself axially as well as laterally in all directions to any torsional strain or twist to which it may be subjected during the use of the instrument.

' An important result of my invention is that I am enabled to dispense with the wooden braces heretofore used upon the sound-board case which tended to deaden the tone and at the same time to attain astructure of greater strength and permanence, insuring an unchangeable foundation for the sound-board. My structure is thus distinguished from the prior state of the art by the abolition of wooden braces upon the sound-board case and by the use of an integral rim-case trussed internally by means of a free centralizinghub and self-adjusting tangential stays. It is not designed to compress the rim, but solely to preserve and maintain its original form intact.

I am aware that tension rods or members have heretofore been known as applied to sounding-board rims and that they have been connected radially to a common coupling-ring secured to the stationary and rigid framework of the piano; but such structures are not the equivalent of mine; neither do they anticipate either in result or design that which I claim as my invention, namely:

1. The combination with a sounding-board and the rim-case to which it is attached, of a series of stay-rods the outer extremities of which are connected with the said rim-case, and the inner extremities of which are connected with a centralizing-hub which is otherwise free and unattached, together with said centralizing-hub supported solely by said rods, and with means for adjusting the tension exerted by said stay-rods, for the purpose set forth.

2. The combination of a sounding-board, a rim-case the parts of which are united integrally and to which said sounding-board is secured, a series of stay-rods the outer extremities of which are connected with the said sounding-board rim-case, and the inner extremities of which are connected with a centralizing-hub which'is otherwise free and unattached, together with said centralizing-hub supported solely by said rods, and means for adjusting the tension exerted by said stay-rods, for the purpose described.

3. The combination of a sounding-board, a rim-case the parts of which are united integrally and to which said sounding-board is attached, a series of stay-rods the outer extremities of which are connected to the said sounding-board rim-case, and the inner extremities of which are connected tangentially with a centralizing-hub which is otherwise free and unattached, said centralizing-hub, and means for adjusting the tension of said stay-rods, for the purpose described.

4:. The combination of a sounding-board, a rim-case the parts of which are united integrally, and to which said sounding-board is attached, a series of stay-rods the outer extremities of which are connected in a common plane, or substantially so, to the sounding-board rimcase, the inner extremities of said stay-rods being connected alternately in different planes to a centralizing-hub in such manner as to truss the said sounding-board rim internally, and means for adjusting the tension of said stay-rods for the purpose described.

5. The combination of a sounding-board rim-case, the parts of which are united integrally and to which said sounding-board is attached, a series of stay-rods the outer extremities of which are connected by universal joints with the said sounding-board rim-case, and the inner extremities of which are connected tangentially with a centralizing-hub which is otherwise free and unattached, said centralizing-hub, and means for adjusting the tension of said stay-rods for the purpose set forth.

6. The combination of a sounding-board, a rim-case the parts of which are united integrally and to which said sounding-board is attached, a series of stay-rods the outer extremities of which are connected in a common plane, or substantially so to said sounding-boardrimcase by means of universal joints, the inner ends of said stay-rods being connected alternately in different planes to a centralizing-hub in such manner as to truss the said soundingboard rim internally, and means for adjusting the tension of said stay-rods, for the purpose set forth.

7. The combination with a sounding-board and the rim-case to which it is attached, of a centralizing-hub free and unattached, and a series of rods connected tangentially with said hub and to the rim-cas e. v

8. The combination with a sounding-board and the rim-case to which it is attached, of a centralizing-hub free and unattached, a series of rods connected tangentially to said hub and to the rim-case, and a self-adjusting bearing between said rods and rim-case.

9. The combination with a sounding-board, the rim-case attached thereto, and the rimbrace, of a centralizing-hub, a series of rods connected tangentially to said hub, and to the rim-case, said hub being otherwise free and unattached, and a self-adjusting bearing between said rods and rim-case and rim-brace.

PAUL MARTIN ZEIDLER.

Witnesses:

D. W. GARDNER, FRANK E. RoAcH. 

